Method of making an inflatable fabric



N v. 14, 1 6 I B. H. FOSTER ETAL 3,008,213

INVENTORS 500777514 bi P087167? M46675 wwaAa BY m .AT TORNEY Nov.14,1961 BHF STER Em 3,008,213

METHOD OF MAKING AN INFLATABLE FABRIC Filed Jan. 22, 1957 2 Sheets-Sheet2 5 H3 /36 41% A35 0'': /Jw

INVENTORS 600177511 6. FOdff/P M48678 f/ADD/ID Y ATTORNEY United StatesPatentOfilice 3,008,213 Patented Nov. 14, 1961 3,008 213 METHOD F MAKINGAid INFLATABLE FABRIC Boutwell H. Foster, Maplewood, and Nassib Haddad,

Iselin, Nl, assignors to United States Rubber Company, New York, N.Y., acorporation of New Jersey Filed Jan. 22, 1957, Ser. No. 635,200 3Claims. (Cl. 28-72) This invention relates generally to the art offabrics and, more particularly, to a two-ply fabric for use in makinginflatable articles and to the method of making the same.

The fabric of this invention has wide application. It is especiallyuseful in manufacturing inflatable articles having the characteristic ofbeing substantially rigid when in inflated condition. Such articlesinclude air mattresses, floats, rafts, temporary shelters in the natureof portable buildings and huts, and the like.

It has been the practice in the past to make many inflatable articlesfrom coated plush loom fabrics and from coated plies of ordinaryfabrics. Articles heretofore made from these fabrics have frequentlybeen objection able for several reasons. In the first place, due tomanufacturing complexities, operational difficulties and theconsiderable amount of hand work involved, the cost of producing thearticles has been necessarily high. Then again, many of the articles donot possess the required degree of rigidity when inflated.

The principal disadvantage of plush loomfabrics is their cost. Plushlooms are much more complex than ordinary looms and are considerablymore expensive. The fabric of the present invention may be readily madeby the use of ordinary looms, thereby substantially reducing manufacturing costs as compared to that of similar fabrics that are made byplush looms.

The primary object of this invention is to provide an improved fabricfor use in making inflatable articles having the characteristic of beingsubstantially rigid when fully inflated.

Another object of the invention is to provide a lightweight, compact,strong, durable, and air-impervious fabric for inflatable articles ofthe type referred to above.

The invention has for a further object the provision of a fabric of thecharacter indicated which may be readily woven by an ordinary loom andwhich is capable of performing its intended functions in an entirelysatisfactory manner.

A preferred and recommended fabric according to this invention compriseswoven first and secondfabric plies positioned one above the other withthe warp yarns and the filler yarns of the first ply extending in thesame direction as the corresponding yarns of the second ply. The fabricis provided with several pluralities of limp binder yarns which arejoined to the plies by weaving along corresponding spaced rows. Eachbinder yarn alternately engages each ply and extends between the pliesin unstressed condition. The juncture of each binder yarn with the firstply in one of the rows is intermediate and substantially equidistantfrom its next preceding and next successive junctures with the secondply. Each ply is provided with a flexible, air-impervious coating whichis substantially coextensive with its outer surface. The fabric has itsparts so constructed and arranged that when it is sealed along its edgesand fully inflated with air, it forms a substantially rigid structurehaving generally planar and parallel walls which are defined by thecoated plies and which are spaced apart to the extent allowed by thebinder yarns.

The warp yarns comprise substantially shrunk heatshrinkable syntheticfilaments. The filler and binder yarns, on the other hand, comprisefilaments that are normally non-shrinkable to a substantial extent, ascompared to the warp yarns. The plies and the binder yarns aresimultaneously woven by means of an ordinary loom prior to shrinking theheat-shrinkable yarns.

The expression heat-shrinkable, as applied to certain yarns andfilaments in this description and in the claims, refers to yarns andfilaments which are adapted to be contracted or shrunk to a substantialextent under heat treatment. Such yarns and filaments may be made of asuitable polyvinyl chloride compound, one of which is now availableunder the name Rhovyl. Filaments of this material may be shrunkapproximately 50% of their original length upon being subjected totreatment at a temperature above F. Other synthetic materials which maybe used for the heat-shrinkable yarns or filaments include polyethyleneand a polyvinyl composition which is presently available under the nameVinyon.

The expression non-shrinkable, as applied to various yarns and filamentsin this description and in the claims, refers to yarns and filamentswhich do not contract or shrink substantially under heat treatment. Thematerials of such yarns and'filaments include cotton, nylon, rayon,wool, silk, and the like.

The enumerated objects and other objects, together with the advantagesof this invention, will be readily under stood by persons versed in theart from the following detailed description and the accompanyingdrawings which respectively describe and illustrate fabrics embodyingthe invention.

In the drawings:

FIG. 1 is an isometric view of a piece of fabric of this invention priorto being shrunk and coated, the relationship of parts being exaggeratedfor purposes of illustration;

FIG. 2 corresponds to FIG, 1 and shows the relative position of theparts of the fabric after it is shrunk but prior to being coated;

FIG. 3 is an isometric view of a portion of an inflat able articleembodying the fabric of this invention;

FIG. 4 is a top plan view of a fabric which is similar to the fabricshown in FIG. 1; and

FIG. 5 is a view taken along line 5-5 of FIG. 4 after the fabric isshrunk.

Referring now to the drawings wherein like reference numerals identifycorresponding parts throughout the several views, we have illustrated inFIGS. 1, 2, 4 and 5 an uncoated fabric 10 which is woven by an ordinaryloom, as distinguished from a plush loom or other special loom. FIGS. 1and 4 illustrate the fabric prior to shrinking and coating, while FIGS.2 and 5 illustrate the fabric after shrinking but prior to coating.

Fabric .10 consists of a first or top fabric ply 11, a second or bottomfabric ply l2, and pluralities of binder yarns 13a, 13b and 13c whichare joined by weaving to the first and second plies. First ply 11comprises warp yarns 14 and filler yarns '15. Second ply 12 compriseswarp yarns 16 and filler yarns 17 which extend in the same direction asthe corresponding yarns of ply 11.

Warp yarns 14 and 16 comprise a heat-shrinkable synthetic material, suchas Rhovyl. Filler yarns 15 and 17 comprise a material which issubstantially non-shrinkable, such as cotton or nylon. Nylon ispreferred for the reason that filaments thereof have high tensilestrength. If desired, the warp yarns may comprise the non-shrinkablematerial while the filler yarns may comprise the heatsuch as nylon orcotton. These yarns are normally limp and substantially unstressed inuninflated articles en1- bodying the fabric. The binder yarns areadapted to be stressed in tension when the article is inflated.

Binder yarns 13a are represented by full lines in FIGS.

l, 2 and 3. Binder yarns 13b are represented by broken lines in FIGS. 1,2 and 3, while binder yarns 130 are represented by dot-dash lines inthese views. It will be observed tha-t binder yarns 13a, 13b and 130 arearranged in repeating groups and their junctures with the first andsecond plies are staggered in each group. This relationship is bestshown in FIGS. 2 and 4.

Each binder yarn extends in the warp direction of the plies andalternately engages each ply and extends be tween the plies insubstantially unstressed condition. The binder yarns are joined to theplies along corresponding rows or lines in the warp direction, as shownin various views. The junctures or connections of one of the binderyarns are identified by corresponding numerals in FIGS. 1 and 2, by wayof example. Reading from left to right in these views, one of binderyarns 13a is first joined to ply 11 at 18, is next joined to ply 12 at19, is next joined to ply 11 at 20, is next joined to ply 12 at 2 1, isnext joined to ply 11 at 22, is next joined to ply 12 at 23, and islastly joined to ply 11 "at 24. All the binder yarns are joined to bothplies in the same manner. Hence, it will be observed that the junctureof each binder yarn with the first ply is intermediate and substantiallyequidistant from its next preceding and next successive junctures withthe second ply. This relationship exists in the fabric before shrinking(FIG. 1) and after shrinking (FIG. 2).

The fabric of FIG. 1 is treated after it leaves the loom in a hot waterbath having a temperature above 160 F. This causes the fabric to shrinkapproximately 50% of its original length due to the warp yarns beingmade of a heat shrinkable material. This brings successive junctures ofeach warp yarn closer together in each ply from their relative locationsshown in FIG. 1 to those shown in FIG. 2, and allows the plies to bespaced apart as illustrated in FIG. 2 to the extent permitted by thesegments of the binder yarns which are positioned between the plies.

The following tables set forth data in respect to typical fabrics ofthis invention:

(b) After shrinking"-.. 3.1.

TABLE 2 Fabric prior and subsequent to being shrunk Before AfterShrinking Shrinking 1. Width, inches 52. 5 44. 75 2. Weight, oz./sq. yd5. 76 12.25 3. Ends/inch of 3-120 denier Rhovy 74 87 4. Picks/inch of210 denier nylon. 46 86 5. Binder yarns/inch of 210 denier nylon 37 43.5 6. Percent Rhovyl in fabric 59. 2 59. 2 7. Percent Nylon in fabric.--40. 8 40. 8 8. Percent Shrinkage in length 46. 5 9. Percent Shrinkage inwidth 14. 8

Reference is next had to FIG. 3, which illustrates part of an inflatablearticle, such as a float 25, that is made from a piece of shrunk fabricof FIG. 2. Prior to making the float, a layer of rubber or othersuitable material is applied to the outer surface of each ply to formthereon a coextensive coating 26 that is flexible and impervious to air.Float includes sealing strips 27 which are made of an appropriatematerial, such as a rubberized fabric, and which are applied to and sealthe edges of the coated fabric to prevent escape of air from itsinterior. A flexible inflating tube 28 is secured to the coated fabricwith the aid of a sealing ring 29 and communir'stes with the spacebetween the fabric plies.

The float may be readily inflated by admitting air under pressurethereinto by Way of tube 28. The air so admitted moves the coated pliesapart to the extent allowed by the portions of the binder yarns betweenthe plies, as shown in FIG. 3. The parts are so constructed and arrangedthat the inflated float is substantially rigid and its walls, which aredefined by the coated plies, are planar and parallel.

From the foregoing, it is believed that the objects and advantages ofthe herein described inflatable fabric and of the method of making thesame, will-be apparent to those skilled in the art, without furtherdescription. It is to be understood, however, that the invention may beembodied otherwise than as here shown and described and that variouschanges may be made without deparb ing from the spirit or sacrificingany of the advantages of the invention.

We claim:

1. In a method of making a fabric of the character described, the stepsof weaving first and second fabric plies having warp yarns extending inone direction and filler yarns extending in another direction, the yarnswhich extend in one of said directions comprising substantiallyheat-shrinkable filaments, connecting the plies with normally limpnon-shrinkable binder yarns to obtain a product wherein the binder yarnsare joined to the plies along spaced rows in a manner that the junctureof each binder yarn with the first ply in one of said rows isintermediate and substantially equidistant from the next preceding andnext succeeding junctures thereof with the second ply, heating saidproduct to substantially shrink the heatshrinkable filaments thereof,and then applying to the outer surface of each ply a material to formthereon a substantially coextensive coating that is flexible andimpervious to air.

2. In a method of making a fabric of the character described, the stepsof weaving first and second fabric plies having heat-shrinkablesynthetic warp yarns that extend in one direction and non-shrinkablefiller yarns that extend in another direction, connecting the plies withnormally limp non-shrinkable binder yarns to obtain a product whereinthe binder yarns arejoined to the plies along spaced rows in a mannerthat the juncture of each binder yarn with the first ply in one of saidrows is intermediate and substantially equidistant from the nextpreceding and next succeeding junctures thereof with the second ply, andheating said product to substantially shrink the warp yarns thereof.

3. In a method of making a fabric of the character described, the stepsof weaving substantially parallel first and second fabric plies havingheat-shrinkable warp yarns extending in one direction and non-shrinkablefiller yarns extending in another direction and simultaneouslyconnecting the plies by weaving with normally limp nonshrinkable binderyarns to obtain a composite fabric wherein the binder yarns are joinedto the plies along spaced rows in a manner that the juncture of eachbinder yarn with the first ply in one of said rows is intermediate andsubstantially equidistant from the next preceding and next succeedingjunctures thereof with the second ply, heating the composite fabric tosubstantially shrink the warp yarns thereof, and then applying to theouter surface of each ply a material to form thereon a substantiallycoextensive coating that is fiexible and impervious to air.

References Cited in the file of this patent UNITED STATES PATENTSWallwork May 24, 1949 Crawford Sept. 5, 1950 Foster Aug. 19, 1952 Mauneyet al. May 1, 1956 McCord et al. Aug. 7, 1956 Paris et a1 Aug. 7, 1956Runton Oct. 30, 1956 FOREIGN PATENTS Great Britain Mar. 14, 1933

1. IN A METHOD OF MAKING A FABRIC OF THE CHARACTER DESCRIBED, THE STEPSOF WEAVING FIRST AND SECOND FABRIC PLIES HAVING WARP YARNS EXTENDING INONE DIRECTION AND FILLER YARNS EXTENDING IN ANOTHER DIRECTION, THE YARNSWHICH EXTEND IN ONE OF SAID DIRECTION COMPRISING SUBSTANTIALLYHEAT-SHRINKABLE FILAMENTS, CONNECTING THE PLIES WITH NORMALLY LIMPNON-SHRINKABLE BINDER YARNS TO OBTAIN A PRODUCT WHEREIN THE BINDER YARNSARE JOINED TO THE PLIES ALONG SPACED ROWS IN A MANNER THAT THE JUNCTUREOF EACH BINDER YARN WITH THE FIRST PLY IN ONE OF SAID ROWS ISINTERMEDIATE